1. Field of the Invention
The present invention relates to a distributed file system and a method of supporting data fault tolerance in the same.
2. Discussion of Related Art
Recently, with the prevalence of smart phones, tablet personal computers (PCs), wearable devices, etc., unstructured high-quality data is continuously increasing, and an increase in the capacity of a cloud storage is becoming problematic. Also, a large amount of data generated from Internet of things (IoT) communication in which things are interconnected and virtualized is stored in a cloud storage, and thus there is an urgent need to develop a cost-effective high-capacity cloud storage technology.
Meanwhile, with the development of an exabyte-level cloud storage, various cost-reduction technologies are being demanded. In particular, efficiency of storage space utilization is considered important for reducing cost in relation to data fault tolerance, and thus technologies related to erasure coding are attracting a great deal of attention. Also, to reduce network construction cost, torus interconnection network technologies employing direct inter-node communications, etc. are on the rise.
Here, the storage erasure coding is a technology for generating parity blocks in data units of a specific size and storing data blocks and the parity blocks in a plurality of nodes in units of a specific size in a distributed manner. In other words, according to storage erasure coding, even when a part of data is lost, it is possible to recover the data through decoding.
A distributed file system generally uses a fat-tree interconnection network in which network loads between servers are the same. However, a fat-tree interconnection network requires a large number of expensive switches for hundreds of or more connections, and thus has limitations in terms of node expandability. Such a problem of expandability of the interconnection network can be solved by a storage network configuration based on a torus interconnection network.
However, when data fault tolerance is supported through the erasure coding in a distributed file system based on a torus interconnection network, transmission loads between nodes vary, unlike those in a fat-tree interconnection network. Also, there may be a case in which it is necessary to pass through an intermediate node for communication between nodes.
Therefore, a distributed file system based on a torus interconnection network currently requires a technology for effectively using erasure coding.
In this regard, Korean Patent Publication No. 10-2013-0093736 (title: Routing system and method using torus topology in on-chip network) discloses a routing system and method for minimizing the size of an additional buffer (virtual channel) through deadlock recovery with tokens (DRT) while still using abundant wires provided by a two-dimensional (2D) torus topology.